// \w \d
let hd = "houdunren2010-";
console.log(hd.match(/\w+/)); // \w表示匹配字符数字下划线, -不是下划线

let email = "2300071698@qq.com";
console.log(/^\w+@\w+\.\w+$/.test(email));

// \W 反向，除了字符数字下划线都匹配
console.log("hdcms@".match(/\W/));

// 5 - 10
console.log(/^[a-z]\w{4,9}$/.test("8houdunren"));
